This strange tick has been going on for years now. I have not noticed a loss in power or any serious valve train malfunctions..yet..but it is on the driver's side somewhere up top. I have used a mechanics stethescope (screwdriver) on the valve cover, fuel pressure regulator (replaced anyway) and the fuel injectors. I have also tried unplugging the plug wires one at a time and still the tick remains. The only time I heard any sound through my screwdriver was when i placed it on the exhaust manifold section for the #1 piston. The tick occurs AFTER the engine is warmed up and ONLY occurs when i am engine braking (5 speed) between 1700 and 1200 RPM then disappears at idle. WHAT IS THIS THING!?

 

I'm thinking exhaust leak. I'd check how tight the nuts are where the manifold and crossover connect to the down pipe. Might even need a new gasket in there if it is leaking.

 

Ive often thought that donut gasket was bad but there isn't any black deposits that I can see? I had a new one from Autozone and it just rolled around in the back and I eventually returned it. I just didn't want to snap off those studs. My old man did that…not a fun fix. Ive heard that the heat shield can cause some issues as well? Rattling, vibrating and the whole range of funny noises?

 

mine does samething, i just thought it was the valves opening and closing?

 

I was always under the impression that if it were the valve the noise would be there all the time not just at certain RPM ranges?

 

its the lifters.....jk lol but i would think it would be something to do with the valve train, try checking clearancesbetween cam and shim?

 

I will have to do that when i replace my leaking valve cover gaskets. I may or may not have tightened down the valve cover too tight. I heard this will cause the cam to tick against the valve cover?